Link

Carries typed links between a resource and related targets such as preload hints.

Use Link for resource hints (rel=preload, rel=preconnect), 103 Early Hints, and 451 legal blockades (rel="blocked-by"). Link-Template is the templated sibling field.

httpheaderperformanceredirects

Reference (http)

Link: </app.css>; rel=preload; as=style, </api/schema>; rel=describedby

Use Link for resource hints (rel=preload, rel=preconnect), 103 Early Hints, and 451 legal blockades (rel="blocked-by"). Link-Template is the templated sibling field.

Common mistakes

Treating Link as a redirect or forgetting as= on preload hints, which breaks their priority benefit.

IANA registry: http-fields/field-names

Registry reference: RFC 8288: Web Linking

HTTP 103 Early Hints HTTP 451 Unavailable For Legal Reasons

Sources

MDN HTTP Reference
IANA HTTP Field Name Registry